Ping monitoring and my WRT54G

Yes another issue with the WRT54G.
I am running a program called Look@Lan. It ping scans my network to see what computers are up and what are down. Every time it scans it brings down the network for maybe 3 secs. Just long enough for all the vpns in my office to disconnect. Is this something that you all think is normal in all routers or do you think this one is just on its way out? Thoughts?